Annual changes in concentrations of PM10, O3 and NO2 in the period 2001–2010

The data presented were derived from a consistent set of stations in all years.
Statistically significant trends (level of significance 0.1) are calculated by applying the Mann-Kendall test. Increasing concentrations are indicated with red dots and decreasing concentrations with green dots, when statistically significant. The applied method is described in de Leeuw, 2012.